The present invention relates to a device for subjecting a shaft to a combined simple rotation and alternating rotation of limited extent about its own axis.
The device can be applied particularly, but not exclusively, to a mechanical plant uprooting system.
In order to remove plants from soil it is in fact conventionally necessary to make an appropriate sod of said soil remain with the roots.
This operation, known as balling and burlapping, currently entails use of a curved blade which is subjected to a combined simple rotation and alternating rotation of limited extent about its own axis.
The simple rotation, combined with the alternating vibrating motion, allows the blade to easily penetrate the soil and to isolate the sod from said soil.
Both movements are actuated by corresponding actuation means which can be constituted, merely by way of example, by a hydraulic motor for the rotary motion and by a generator of torsional oscillations for the vibrating motion.
The main problem affecting currently commercially available devices resides in the breakages that occur in the elements that associate the blade supporting shaft with the actuation means and by the considerable dimensions of the devices.